/* bzflag
 * Copyright (c) 1993-2020 Tim Riker
 *
 * This package is free software;  you can redistribute it and/or
 * modify it under the terms of the license found in the file
 * named COPYING that should have accompanied this file.
 *
 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */


// common goes first
#include "common.h"

// implementation header
#include "bzglob.h"

// system headers
#include <string>


static int match_multi (const char **pattern, const char **string);

static const char MATCH_MULTI  = '*'; // matches any number of characters
static const char MATCH_SINGLE = '?'; // matches a single character


/******************************************************************************/

bool glob_match (const std::string& pattern, const std::string& string)
{
    return glob_match (pattern.c_str(), string.c_str());
}

/******************************************************************************/

bool glob_match (const char *pattern, const char *string)
{
    if (pattern == NULL)
        return false;
    if (string == NULL)
        return false;

    if ((pattern[0] == MATCH_MULTI) && (pattern[1] == '\0'))
        return true;

    while (*pattern != '\0')
    {
        if (*pattern == MATCH_MULTI)
        {
            pattern++;
            switch (match_multi (&pattern, &string))
            {
            case +1:
            {
                return true;
            }
            case -1:
            {
                return false;
            }
            }
        }
        else if (*string == '\0')
            return false;
        else if ((*pattern == MATCH_SINGLE) || (*pattern == *string))
        {
            pattern++;
            string++;
        }
        else
            return false;
    }

    if (*string == '\0')
        return true;
    else
        return false;
}

/******************************************************************************/

static int match_multi (const char **pattern, const char **string)
{
    const char *str = *pattern;
    const char *obj = *string;

    while ((*str != '\0') && (*str == MATCH_MULTI))
    {
        str++; // get rid of multiple '*'s
    }

    if (*str == '\0')   // '*' was last, auto-match
        return +1;

    const char *strtop = str;
    const char *objtop = obj;

    while (*str != '\0')
    {
        if (*str == MATCH_MULTI)
        {
            *pattern = str;
            *string = obj;
            return 0; // matched this segment
        }
        else if (*obj == '\0')
        {
            return -1; // can't match
        }
        else
        {
            if ((*str == MATCH_SINGLE) || (*str == *obj))
            {
                str++;
                obj++;
                if ((*str == '\0') && (*obj != '\0'))   // advanced check
                {
                    obj++;
                    objtop++;
                    obj = objtop;
                    str = strtop;
                }
            }
            else
            {
                obj++;
                objtop++;
                obj = objtop;
                str = strtop;
            }
        }
    }

    *pattern = str;
    *string = obj;

    return +1; // full match
}


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